Sonos Amp and High level input from Subwooder?

This, from the horse's mouth:
https://relsupport.zendesk.com/hc/en-us/articles/115004649588-How-do-I-stop-my-subwoofer-from-humming-

Also see if the hum goes away by connecting both the amp and the REL to the same wall power socket, and stays away without the cable from the LFE to the Amp.

More intriguing results on googling from REL:

https://relsupport.zendesk.com/hc/en-us/articles/227195467-Tzero-Sonos-A-connectivity-Update

I know that this link does not refer to your specific model and this is referenced in the linked article, but I have not been able to find the link for another article mentioned that does.

But this one is interesting because it says that with Sonos, only a low level connection is recommended.

I also think that the article is not being completely honest is using as an excuse the Sonos lack of Hi Res capability to say that if you use low level connection, it is still ok because Sonos does not go the distance anyway as far as sound quality is concerned, so what is a little loss of Sub integration quality by using the low level connection? Hogwash, that excuse.

It seems to me that REL and Sonos are not a happy pairing. Perhaps due to the Sonos sleep mode feature as the article suggests, perhaps something else. After all this research I would not use REL with Sonos kit. In any case, I use the Sonos Sub for music and it does all I expect a Sub to, bonded to a play 1 pair.

So i've not had luck with the high level connection, still getting a hum regardless of how I tried to do the ground.

I'm testing between using the Low level connection, and the LFE now to the Amp Sub out.

The only issue I have with the low level connection, is that the bass and gain seem to be considerably lower than the LFE, not sure yet if it's normal or just has to be turned up a bit.

I know theoretically LFE is for movies, but I'll see what type of bass response it gives me and if I can still adjust crossover. (The app allows me to, just need to confirm by listening that's working)

I wonder what are the downsides of using LFE for music, aside from the crossover being at 80hz? Does it strip out any other things?

No idea; I haven't used REL. The only additional information I have gleaned is that where the Sonos Amp is concerned, the frequency stripping at the speaker terminals happens only if something is plugged into the Sub out on the Amp AND that Sub is turned on in the Sonos app, under settings for the Amp in room settings. Even if that something is just a blank jack. So if you make sure that the Sub is turned off, you should not lose anything by wiring the Sub out to the LFE in as suggested by REL for hum elimination. If you do this, and let the black lead of REL float unconnected, according to REL there should be no hum for high level connections to class D amps like the Sonos Amp.

Just my opinion, but I I find fault with Sonos for not allowing the sub output to be used without engaging the crossover. They could easily fix that with a firmware update, I would think. Maybe they will if enough people bug them. I sent an email asking for this a month or two ago.

Just curious; why do you need this? To present the main speakers with the full signal or to do the same to the Sub, using the Sub crossover for filtering?
And for getting either/both, won't high level connections work - the REL seems to have hum issues with these, but that seems to be a REL thing, not one related to high level connections as such.

Just curious; why do you need this? To present the main speakers with the full signal or to do the same to the Sub, using the Sub crossover for filtering?
And for getting either/both, won't high level connections work - the REL seems to have hum issues with these, but that seems to be a REL thing, not one related to high level connections as such.
I like to cross over with a sub as low as possible, if main speakers go there. If they roll off smoothly at the low end then I just cross over using the filter in the sub while feeding main speakers full range. As you say, an option with the Sonos Amp is to feed the sub a speaker level signal to do this. But that is not always the nicest option, Or there might be a problem with this, like hum that the OP of this thread is having. I just don't understand why Sonos would not have the option to output full range to the main speakers with sub output connected.

I just don't understand why Sonos would not have the option to output full range to the main speakers with sub output connected.
No idea; it isn't there in the Connect Amp either. And in the Connect Amp, the crossover is set at 80hz, no choices; of course if a Sonos Sub is being added, crossover can be chosen from 50Hz to 110 Hz. I remember seeing that the Sonos Amp offers this option for third party Subs as well, so that should address your needs. I can't see that much would be lost regardless of how capable the main speakers are for low frequencies, if the crossover is set to as low as 50hz.

I remember seeing that the Sonos Amp offers this option for third party Subs as well, so that should address your needs. I can't see that much would be lost regardless of how capable the main speakers are for low frequencies, if the crossover is set to as low as 50hz.
Yes, the amp does work with 3rd party subs this way. That is how I am using it, with the 50hz crossover setting (my main speakers go to about 45Hz). But with main speakers that go a little lower than this I might not want to run it this way. I appreciate when manufacturers try to give customers as much flexibility as reasonably possible, and also when they are open about providing technical information. I think Sonos comes up short here, even though I have been happy with their products.

In many respects, Sonos product design is for a target market that does not want/need such information or flexibility. Which is why audiophiles won't buy into Sonos, but I don't think Sonos cares about the consequent loss of that little market.